scholarly journals Monoclinic and Orthorhombic NaMnO2 for Secondary Batteries: A Comparative Study

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1230
Author(s):  
Jessica Manzi ◽  
Annalisa Paolone ◽  
Oriele Palumbo ◽  
Domenico Corona ◽  
Arianna Massaro ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Reversible Capacity ◽  
Beta Phase ◽  
X Ray Diffraction ◽  
Positive Electrodes ◽  
Detailed Structural Analysis ◽  
Physico Chemical ◽  
Sodium Batteries ◽  
The Impact ◽  
First Time

In this manuscript, we report a detailed physico-chemical comparison between the α- and β-polymorphs of the NaMnO2 compound, a promising material for application in positive electrodes for secondary aprotic sodium batteries. In particular, the structure and vibrational properties, as well as electrochemical performance in sodium batteries, are compared to highlight differences and similarities. We exploit both laboratory techniques (Raman spectroscopy, electrochemical methods) and synchrotron radiation experiments (Fast-Fourier Transform Infrared spectroscopy, and X-ray diffraction). Notably the vibrational spectra of these phases are here reported for the first time in the literature as well as the detailed structural analysis from diffraction data. DFT+U calculations predict both phases to have similar electronic features, with structural parameters consistent with the experimental counterparts. The experimental evidence of antisite defects in the beta-phase between sodium and manganese ions is noticeable. Both polymorphs have been also tested in aprotic batteries by comparing the impact of different liquid electrolytes on the ability to de-intercalated/intercalate sodium ions. Overall, the monoclinic α-NaMnO2 shows larger reversible capacity exceeding 175 mAhg−1 at 10 mAg−1.

Understanding of Lithium Insertion into λ-MnO2 Compounds

1998 ◽  
Vol 548 ◽  
Author(s):  
S. Sarciaux ◽  
A. Le Gal La Salle ◽  
A. Verbaere ◽  
Y Piffard ◽  
D. Guyomard
Keyword(s):  
Oxygen Content ◽  
Structural Parameters ◽  
Reversible Capacity ◽  
Rechargeable Batteries ◽  
Structural Water ◽  
Synthesis Conditions ◽  
Starting Compound ◽  
Physico Chemical ◽  
New Compounds

ABSTRACTA large variety of EMD and HTMD samples with various oxygen and water contents and various structural parameters Pr and Mt has been prepared. We show that the physico-chemical and structural parameters of the λ-MnO2 compounds are related to the synthesis conditions. New compounds were obtained with unusual amounts of intergrowth and twinning defects.The Li insertion study focuses on a comprehensive investigation of the relationships between the material characteristics of the samples and their Li insertion behavior, and on the structural characterization of selected compounds after cycling. The oxygen content drastically affects the shape of the discharge curve after the first cycle and the total reversible capacity. The amount of structural water has an influence on the transformation kinetics of the starting phase. For optimized oxygen content (y= 2 in MnOY), the intrinsic reversible Li insertion capacity is maximum when the amount of microtwinning defects is minimum and when the structure is either mostly Ramsdellite or faulted Pyrolusite. Results show that, upon cycling, the λ-MnO2 structure seems to evoluate towards less Pyrolusite defects together with the apparition of new kinds of defects.This work shows that λ-MnO2, compounds could be good candidates for the cathode application of Li-metal rechargeable batteries, provided that the physico-chemical and structural parameters of the starting compound are well chosen.

scholarly journals Cyclam-Based Chelators Bearing Phosphonated Pyridine Pendants for 64Cu-PET Imaging : Synthesis, Physico-Chemical Studies, Radiolabeling and Bioimaging.

2020 ◽  
Author(s):  
Richard Knighton ◽  
Thibault Troadec ◽  
Valerie Mazan ◽  
Patricia La Saëc ◽  
Séverine Marionneau-Lambot ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Copper Complexes ◽  
The Body ◽  
Renal Elimination ◽  
X Ray Diffraction ◽  
Physico Chemical ◽  
Chemical Studies ◽  
First Time ◽  
Excellent Stability

Herein we present the preparation of two novel cyclam-based macrocycles (te1pyp and cb-te1pyp), bearing phosphonate-appended pyridine side-arms for the coordination of copper(II) ions in the context of 64Cu PET imaging. The two ligands have been prepared through conventional protection-alkylation sequences on cyclam, and their coordination properties have been thoroughly investigated. The corresponding copper complexes have been fully characterized in the solid-state (X-Ray diffraction analysis) and in solution (EPR and UV-Vis spectroscopies). Potentiometric studies, combined with spectrometry, have also allowed us to determine their thermodynamic stability constants, confirming their high affinity for copper(II) cations. The kinetic inertness of the complexes has also been verified by acid-assisted dissociation experiments, enabling their use in 64Cu-PET imaging in mice for the first time. Indeed, the two ligands could be quantitatively radiolabeled under mild conditions, and the resulting 64Cu complexes have demonstrated excellent stability in serum. PET imaging demon-strated a set of features emerging from the combination of picolinates and phosphonate units: high stability in vivo, fast clear-ance from the body via renal elimination, and most interestingly, very low fixation in the liver. The latter is in contrast with what was observed for monopicolinate cyclam (te1pa), that had a non-negligible accumulation in the liver, owing probably to its different charge and lipophillicity. These results thus pave the way for the use of such phosphonated pyridine chelators for in vivo 64Cu-PET imaging.

scholarly journals Cyclam-Based Chelators Bearing Phosphonated Pyridine Pendants for 64Cu-PET Imaging : Synthesis, Physico-Chemical Studies, Radiolabeling and Bioimaging.

2020 ◽  
Author(s):  
Richard Knighton ◽  
Thibault Troadec ◽  
Valerie Mazan ◽  
Patricia La Saëc ◽  
Séverine Marionneau-Lambot ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Copper Complexes ◽  
The Body ◽  
Renal Elimination ◽  
X Ray Diffraction ◽  
Physico Chemical ◽  
Chemical Studies ◽  
First Time ◽  
Excellent Stability

Herein we present the preparation of two novel cyclam-based macrocycles (te1pyp and cb-te1pyp), bearing phosphonate-appended pyridine side-arms for the coordination of copper(II) ions in the context of 64Cu PET imaging. The two ligands have been prepared through conventional protection-alkylation sequences on cyclam, and their coordination properties have been thoroughly investigated. The corresponding copper complexes have been fully characterized in the solid-state (X-Ray diffraction analysis) and in solution (EPR and UV-Vis spectroscopies). Potentiometric studies, combined with spectrometry, have also allowed us to determine their thermodynamic stability constants, confirming their high affinity for copper(II) cations. The kinetic inertness of the complexes has also been verified by acid-assisted dissociation experiments, enabling their use in 64Cu-PET imaging in mice for the first time. Indeed, the two ligands could be quantitatively radiolabeled under mild conditions, and the resulting 64Cu complexes have demonstrated excellent stability in serum. PET imaging demon-strated a set of features emerging from the combination of picolinates and phosphonate units: high stability in vivo, fast clear-ance from the body via renal elimination, and most interestingly, very low fixation in the liver. The latter is in contrast with what was observed for monopicolinate cyclam (te1pa), that had a non-negligible accumulation in the liver, owing probably to its different charge and lipophillicity. These results thus pave the way for the use of such phosphonated pyridine chelators for in vivo 64Cu-PET imaging.

scholarly journals Description of soil impurity for Elbasan city – Albania

2020 ◽  
Vol 13 (2) ◽  
pp. 240-244
Author(s):  
Anila Jançe ◽  
Valentin Bogoev ◽  
Admir Jançe
Keyword(s):  
Heavy Metals ◽  
Soil Pollution ◽  
Scientific Paper ◽  
Chemical Parameters ◽  
Productive Activities ◽  
Physico Chemical ◽  
Current Assessment ◽  
The Impact ◽  
First Time ◽  
Geographical Space

This scientific paper enables us to present the bacteriological, physico-chemical parameters and heavy metals present in the soil of Elbasan city. Through this study we have obtained significant data that give us the opportunity to judge about soil impurity of Elbasan city, allowing us to present a current assessment of soil pollution. The pollution of the land of a historical-cultural city like Elbasan takes on a considerable importance in terms of the impact on the health of citizens, based mainly on the cultivation of agricultural crops in the study area. In view of this goal, during the September-October 2020 period, some soil samples were taken and analyzed in the laboratory, where the area predetermined by us for samples taking consists of the geographical space where the heavy industries of Elbasan city operate. All bacteriological, physico-chemical parameters and heavy metals part of the soil of Elbasan are presented for the first time in this paper. As a result of the results obtained where we encounter a significant soil pollution of Elbasani town we think that is attributed to the fact that Elbasan has always been considered as one of the most polluted cities in Albania in recent years. Finally, we can say that land pollution comes as a result of productive activities of light and heavy industries, which operate without implementing the rules of environmental protection in Albania but also from human activity mainly in agriculture, where we mention the use without criteria of pesticides and chemical fertilizers.

scholarly journals Improving Ultraviolet Responses in Cu2ZnSn(S,Se)4 Thin-Film Solar Cells Using Quantum Dot-Based Luminescent Down-Shifting Layer

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1166
Author(s):  
Woo-Lim Jeong ◽  
Junsung Jang ◽  
Jihun Kim ◽  
Soo-Kyung Joo ◽  
Mun-Do Park ◽  
...  
Keyword(s):  
Solar Cells ◽  
Quantum Dot ◽  
Wavelength Conversion ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Solar Cell Performance ◽  
The Impact ◽  
First Time

Quantum dot (QD)-based luminescent down-shifting (LDS) layers were deposited on Cu2ZnSn(S,Se)4 (CZTSSe) solar cells via the drop-casting method. The LDS layers can easily widen the narrow absorption wavelength regions of single-junction solar cells and enable improvement of the short-circuit current. The optical properties of LDS layers deposited on glass and containing different QD contents were analyzed based on their transmittance, reflectance, and absorbance. The absorber films to be used in the CZTSSe solar cells were determined by X-ray diffraction measurements and Raman spectroscopy to determine their crystal structures and secondary phases, respectively. The completed CZTSSe solar cells with LDS layers showed increased ultraviolet responses of up to 25% because of wavelength conversion by the QDs. In addition, the impact of the capping layer, which was formed to protect the QDs from oxygen and moisture, on the solar cell performance was analyzed. Thus, a maximal conversion efficiency of 7.3% was achieved with the 1.0 mL QD condition; furthermore, to the best of our knowledge, this is the first time that LDS layers have been experimentally demonstrated for CZTSSe solar cells.

scholarly journals Linear-nonlinear optical, dielectric and surface microscopic investigation of KH2PO4 crystal to uncover the decisive impact of dopant glycine

2018 ◽  
Vol 36 (4) ◽  
pp. 662-667 ◽  
Author(s):  
Imran Khan ◽  
S. Kalainathan ◽  
M.I. Baig ◽  
Mohd Shkir ◽  
S. Alfaify ◽  
...  
Keyword(s):  
Second Harmonic ◽  
Structural Parameters ◽  
Microscopic Investigation ◽  
X Ray Diffraction ◽  
Kdp Crystal ◽  
Device Applications ◽  
Optical Dielectric ◽  
Evaporation Technique ◽  
The Comparative Study ◽  
The Impact

AbstractPresent investigation has been started to perform the comparative study of pure and glycine doped KH2PO4 (KDP) single crystals grown by most commercial slow solvent evaporation technique. The grown crystals were subjected to single crystal X-ray diffraction analysis to determine their structural parameters. The linear optical studies of pure and glycine doped KDP crystal have been undertaken within 200 nm to 1100 nm wavelength range by means of UV-Vis studies. The enhancement in second harmonic generation (SHG) efficiency of glycine doped KDP crystal has been determined using a standard Kurtz-Perry powder test. The dielectric measurements have been carried out to explore the impact of glycine dopant on dielectric constant and dielectric loss of KDP crystal. The surface growth habitat and etch pit density of glycine doped KDP crystal have been evaluated using the results of microscopic etching studies. In light of obtained results the suitability of glycine doped KDP crystal for device applications has been discussed.

scholarly journals Comparison of the In Vitro and Ex Vivo Permeation of Existing Topical Formulations Used in the Treatment of Facial Angiofibroma and Characterization of the Variations Observed

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1060
Author(s):  
Guillaume Le Guyader ◽  
Bernard Do ◽  
Victoire Vieillard ◽  
Karine Andrieux ◽  
Muriel Paul
Keyword(s):  
Ex Vivo ◽  
Thermodynamic Activity ◽  
Physico Chemical ◽  
Ex Vivo Permeation ◽  
Franz Cells ◽  
Great Heterogeneity ◽  
The Impact ◽  
First Time

Rapamycin has been used topically to treat facial angiofibromas associated with tuberous sclerosis for more than a decade. In the absence of a commercial form, a large number of formulations have been clinically tested. However, given the great heterogeneity of these studies, particularly with regard to the response criteria, it was difficult to know the impact and thus to compare the relevance of the formulations used. The objective of this work was therefore to evaluate the link between the diffusion of rapamycin and the physico-chemical characteristics of these different formulations on Strat-M® membranes as well as on human skin using Franz cells. Our results underline the importance of the type of vehicle used (hydrogel > cream > lipophilic ointment), the soluble state of rapamycin and its concentration close to saturation to ensure maximum thermodynamic activity. Thus, this is the first time that a comparative study of the different rapamycin formulations identified in the literature for the management of facial angiofibromas has been carried out using a pharmaceutical and biopharmaceutical approach. It highlights the important parameters to be considered in the development and optimization of topical rapamycin formulations with regard to cutaneous absorption for clinical efficacy.

scholarly journals Sustainable Route for Synthesizing Aluminosilicate EU-1 Zeolite

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1462
Author(s):  
Hao Xu ◽  
Jie Zhu ◽  
Xiong Wang ◽  
Chao Shen ◽  
Shengshen Meng ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Hydrothermal Condition ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Synthesis Conditions ◽  
Inductively Coupled ◽  
Water As Solvent ◽  
Icp Analysis ◽  
The Impact ◽  
First Time

Developing sustainable routes for the synthesis of zeolites is still a vital and challenging task in zeolite scientific community. One of the typical examples is sustainable synthesis of aluminosilicate EU-1 zeolite, which is not very efficient and environmental-unfriendly under hydrothermal condition due to the use of a large amount of water as solvent. Herein, we report a sustainable synthesis route for aluminosilicate EU-1 zeolite without the use of solvent for the first time. The physicochemical properties of the obtained EU-1 zeolite are characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA), N2 sorption, inductively coupled plasma (ICP) analysis, and solid nuclear magnetic resonance (NMR), which show the product has high crystallinity, uniform morphology, large BET surface area, and four-coordinated aluminum species. Moreover, the impact of synthesis conditions is investigated in detail. The sustainable synthesis of aluminosilicate EU-1 zeolite under solvent-free

Structural and Electrochemical Investigation of Na+ Insertion Into λ-Mn1-xNixO2

2015 ◽  
Vol 1810 ◽  
Author(s):  
J. R. Kim ◽  
G. G. Amatucci
Keyword(s):  
High Voltage ◽  
Low Cost ◽  
Electrochemical Techniques ◽  
Positive Electrode ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Positive Electrodes ◽  
Insertion Mechanism ◽  
First Time

AbstractIncreased demand for low cost energy storage options has expanded the scope of Na+ batteries considerably; and with the growing interest in Na-based chemistries, the importance of high voltage positive electrodes is quickly realized as the Na/Na+ redox introduces lower operating voltages as compared to Li/Li+ based electrochemical cells. The 4.7V LiMn1.5Ni0.5O4 spinel has exhibited considerable properties as a high voltage Li+ positive electrode, with a host structure (λ-Mn0.75Ni0.25O2) that may provide an analogous high voltage Na+ positive electrode. Structural and electrochemical properties of NaxMn1.56Ni0.44O4 and NaxMn2O4 are investigated for the first time[1] utilizing ex-situ, in-situ X-ray diffraction, and high-resolution electrochemical techniques to provide an insightful study of the Na+ insertion mechanism.

scholarly journals Ostracods as freshwater pollution indicators: a case study from the Ouseburn, a polluted urban catchment (Tyneside, NE England)

2007 ◽  
Vol 26 (2) ◽  
pp. 117-125 ◽  
Author(s):  
Ian Boomer ◽  
Frances Attwood
Keyword(s):  
Water Quality ◽  
Water Quality Assessment ◽  
Urban Catchment ◽  
Biological Water ◽  
Physico Chemical ◽  
The Impact ◽  
First Time ◽  
The Relationship ◽  
Pollution Events

Abstract. The relationship between ostracod occurrence and water quality is investigated in the Ouseburn (Newcastle upon Tyne, NE England) in both a spatial and temporal context. For the first time, ostracod assemblages are used alongside traditional biological water quality indices. Physico-chemical parameters of the water are used in conjunction with standard macro-invertebrate-based biological indices (BMWP, ASPT) to assess general water quality. This is also the first detailed study of ostracod occurrence within a small urban catchment. Ostracod, macro-invertebrate and environmental samples were taken during the summer of 2001, with a small number of late autumn replicates taken to characterize the impact of known pollution events. The pollutants encountered in this study are primarily organic in nature and include sewage, agricultural sources (such as slurry) and de-icer runoff from the local airport. The head-water and tributaries are generally characterized by good water quality despite a number of pollution events recorded during the study. Ostracod diversity and abundance, although often low, support the evidence from the traditional methods of water quality assessment, both of which decrease downstream. An inverse relationship observed between ostracod abundance and macro-invertebrate indices suggests that relatively clean-water macro-invertebrate assemblages out-compete the ostracods or may be preying upon them.

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